An improved screw pump such as, for example, a twin screw pump, includes a casing including an internal chamber, and first and second rotors rotatably positioned within the chamber of the casing. The first and second rotors have an intermeshing threaded-shape profiling. A plurality of bearing seal assemblies are provided at each end of the first and second rotors. Each bearing seal assembly includes a bearing positioned about an end portion of a rotor to facilitate rotation of the rotor, and a seal positioned about an end portion of a rotor to seal passage of the rotor through the casing. The bearing is coupled to the seal so that the seal may be secured to the casing via the coupling of the bearing to the casing.

The disclosure relates to a pump assembly for a vehicle having an internal combustion engine with or without transmission or electric motor with transmission or for an oil supply having a double-pipe pump, wherein the two pipes are separated from each other and a second pipe can be connected to a first pipe, wherein the pump has at least one input drive point for an electric machine and also for a drive motor, including, for example, via a gearbox.

A first communication groove (38) extending from a start point of a discharge port (36) in a direction opposite to rotation direction of vanes (22) is formed. A first end portion (38E) of this groove is connected to the start point of the discharge port (36). When a front-side vane in a rotation direction of a driving shaft (11) is positioned at the start point of the discharge port (36), a second end portion (38S) of the groove is positioned at a rear side in the rotation direction with respect to a rear-side vane coming immediately after the front-side vane, and communicates with a suction port (35). A part of working fluid in a front-side pump chamber (27-1) can therefore be introduced into a rear-side pump chamber (27-2) that communicates with the suction port (35), thereby lessening excessive pressure increase of the front-side pump chamber (27-1) and suppressing pulsation phenomenon.

Rotor and/or stator designs and methods thereof to improve progressive cavity motor or pump durability. In one or more implementations, the rotor may have a variable outer diameter or variable stiffness along an axial length thereof. The stator may similarly have a variable inner diameter or variable stiffness, which may compliment or diverge from the variable outer diameter or variable stiffness of the rotor.

An outer gear and an inner gear expand and contract volume of pump chambers formed between both the gears, and rotate to suction fuel into the pump chambers and then discharge fuel from the pump chambers sequentially. The inner gear includes an insertion hole that is depressed along its axial direction. A joint member includes a main body portion that is fitted to a rotary shaft, a foot portion that extends from the main body portion along the axial direction and is inserted in the insertion hole with a clearance therebetween, and a protruding portion that protrudes from the foot portion toward a rotation progress side of the inner gear and has its width in the axial direction further narrowed toward a top portion of the protruding portion.

This pump comprises: a housing comprising a body and a first partition which separates first and second areas; a stator disposed in the housing; a circuit board disposed in the first area; a pump gear disposed in the second area; and magnets disposed on the pump gear, wherein the second area includes a second space defined by the first partition wall and the body, and the stator is inserted into the body.

A rotary pump is presented for use in a medicament delivery device, where the pump has a back plate having an inner surface and a rotor housing is positioned adjacent to the back plate having a peripheral wall. A front plate support is connected to the back plate and a flexible front plate is positioned between the front plate support and the rotor housing. The pump is rotated using a planetary gear transmission, where an eccentric shaft is operatively connected to the planetary gear mechanism. A rotor is rotationally fixed to the eccentric shaft and movably positioned within the rotor housing. The rotor has three lobes, where each lobe has two peripheral curved surfaces sharing a common apex, where a first portion of each peripheral surface adjacent to the apex defines a non-smooth curve.

A scroll compressor includes oil in an oil storage space that is brought into direct contact with and stirred with a discharge refrigerant. The scroll compressor includes a fixed scroll, an orbiting scroll coupled to one side of the fixed scroll, and a discharge cover coupled to another side of the fixed scroll and provided with a muffler hole communicating with a refrigerant discharge space and the oil storage space.

A rotary cylinder piston compressor pump is provided, including a rotating shaft (2), a piston (3) and a cylinder (4). A rotating shaft hole (21) is provided in the rotating shaft (2). An oil guiding channel, provided in the cylinder (4), communicating with the rotating shaft hole (21). A recess (45) is formed in the inner end face of the cylinder (4). An oil path (61) sealed relative to a compression cavity (49) of the cylinder (4) is formed between the recess (45) and the piston (3). The oil path (61) between the recess (45) and the piston (3) is communicated with an oil path (62) between the piston (3) and the rotating shaft (2) and is communicated with the oil guiding channel by means of an oil returning channel. Also provided is a compressor including the compressor pump.

An improved screw-spindle pump, particularly for cooling systems, includes a first screw, a second screw and a pump housing, inside which the first screw and the second screw are rotatably housed between the first screw, the second screw and the pump housing, being defined pumping chambers adapted to move, as a consequence of the rotation of the first screw and the second screw, a fluid from a suction area to a delivery area of the pump.

The pump housing housing the first screw and the second screw is made in one piece.